Bit-stock



(No Model.)

L. L. DAVIS.

BIT-STOCK.

Patented July 15, 1890.

y 11,'1/ l' i lllllllllllllil UNITED STATES PATENT OEETCE.

LEONARD L. DAVIS, OF SPRINGFIELD, MASSACHUSETTS.

BIT-STOCK.

SPECIFICATION forming part of Letters Patent No. 432,180, dated July 15, 1890. Application filed January 13, 1890. Serial No. 336,757. l(No model.)

T0 all whont t may concern:

Be it known that I, LEONARD L. DAVIS, a citizen of the United States, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Bit-Stocks, of which the following is a specification.

This invention relates to bit-stocks, and has reference particularly to an improved equipment of jaws and shank-socket therefor adapted to receive the engagement therewith of said jaws; and the invention consists in the peculiar construction and arrangement of said parts, all as hereinafter fully described, and pointed out in the claim.

In the drawings forming part of this specific-ation, Figure l is a side elevation of the lower end of the bit-stock and a longitudinal section of the tool-socket and its screw-sleeve, showing therein, in edge View, the jaws of the implement, all embodying my improvements. Fig. 2 is a cross-section on line 2 2, j

Fig. l. Fig. 3 is a perspective view of one of the jaws. Fig. 4 is a perspective view of a jaw of a slightly-modified construction.

In the drawings, A is the lower end of a bitstock of the usual metallic construction, and B is the tool-socket exteriorly screw-threaded and having the j aw-operatin sleeve D screwing freely thereon in the usual manner.

Each of the two jaws 7L consists of a head 3, suitablygrooved to grasp a tool placed between them, and a spring-shank 4, having a stud 5 formed therein or rigidly attached thereto, the sides of which are plain or smooth, which is located nearone end of said springshank extending at right angles to the side thereof. The said tool-socket has the usual longitudinal recess G therein to receive the shank of the tool that may be held and turned by the bit-stock, and in opposite sides of said socket B are formed two longitudinal grooves 7 for the reception therein of the said jaws h, wherein they occupy the positions shown in Fig. l, and in said socket at the inner end of said grooves is smoothly bored a cylindrical socket to receive the said studs 5 on the shanks of the jaws 7L, as clearly shown in said lastnamed figure. The bottom of each of said grooves 7 nearly from the inner to the outer end thereof is inclined toward the axis of the socket B, said inclination beginning a little forward of the sockets which receive the studs 5 of the jaws h, in order to form at the side of each of said sockets a salient point on or across which that part of the spring-shank 4 of the jaw h near its stud 5 may bear when the heads 3 thereof are forced toward each other, as below described, and whereby the reaction of the spring-shanks to throw the jaw-heads apart is made more effective. The said screwthreaded sleeve D incloses the said socket B and spring-jaws h, as shown, and has a spherical head S, the inner curved side of which is forced against the heads 3 of the jaws h, thereby forcing them together and against the shank of a tool-piece in the bit, thereby holding said tool firmly. Screwing said sleeve outwardly or more or less off from the socket B permits the j aw-heads 3 to spring apart or separate, so that said tool maybe removed from the bit.

Bit-stocks which have heretofore been made with jaws embodying spring-shanks forming a part thereof have been held in place on the tool-socket part B by the provision of screws which have been by their shanks passed freely through perforations in the extremities of said jaw-shanks and with a screw engagement into the tapped transverse holes in the tool-socket part of the stock, the heads of the screws having borne upon the outer sides of the j avv-shanks. In the assemblage of the parts of such a bit-stock the turning in of the screws to hold the jaws on the socket part is tedious and requires considerable time. Vhile under this invention the smooth stud affixed as one onto the springjaw by one movement may be readily inserted in the smooth-bored socket therefor in the socket part B. Of course the spring-shank may be as readily detached from the said socket part B, and yet when it is engaged therewith its engagement is as efficient as if made with the screws. It will be mentioned that it is deemed undesirable to employ the screws, fora reason further than above stated --namely, such screws are usually machine-made, and in the eventof one becoming lostfrom the bit-stock may not readily be replaced.

Fig. 4 illustrates a jaw having a springshank 4, which is made of a separate piece of spring metal and riveted or otherwise similarly fixed thereon. This modification of the IOO manner of making said spring-jaw, as compaired with that shown in Fig. 3, results in the production of a jaw having substantially the same function as that shown in said lastnamed figure; but it is less durable in 'use and requires more operations in its manufacture, for the jaw shown in Fig. 3 may be made of a single piece ot' metal by drop-forging it.

What I claim as my invention is- The combination,with the tool-socketpart B of a bit-stock provided With the 1ongitudinal depressions 7 7 and the smooth bored sockets extending laterally and inwardly from the bases of said depressions, of the jaws 7L h, having spring-Shanks, and the smooth studs 5 5, formed on and laterally extended from the sides of the Shanks, and said studs adapted when the said jaws are in place in their respective depressions 7 therefor to freely enter the said smooth sockets, all substantially as described and shown, and for the purposes set forth. 4

LEONARD L. DAVIS. Witnesses:

H. A. CHAPIN, K. E. BELLoWs. 

